Whether you've decided to formula feed your baby from the start, are supplementing your breast milk with formula, or are switching from breast milk to formula, you're bound to have questions. Here are answers to some common queries about formula feeding.

My baby is fussy after a feeding. How can I help?

Babies can be fussy for a number of reasons. Sometimes it's due to gas, or the the type of formula, bottle, or nipple used, or something else entirely. The tips below may help your baby feel more comfortable.

Walk with your baby or sit in a rocking chair, trying various positions.

Try burping your baby more often during feedings.

Place your baby belly-down across your lap and rub his or her back.

Put a warm towel or warm water bottle on your baby's belly, checking first to make sure it's not too hot.

Hold your baby upright.

Put your baby in a swing — the motion may have a soothing effect.

Put your baby in an infant car seat in the back of the car and go for a ride. The vibration and movement of the car often calm a baby.

Try playing music — some babies respond to sound as well as movement.

Try turning on the dishwasher, clothing dryer, or a white noise machine. The continuous gentle noise may sooth a crying baby.

How do I know if my baby has an allergy?

Report any of these symptoms to your baby's doctor, and follow his or her advice on switching to a special hypoallergenic formula. But even if the doctor suspects an allergy, don't spend too much time worrying that your child might be allergic forever. Kids often outgrow milk protein allergies within a few years.

Is soy formula safe for my baby?

Most doctors usually recommend giving babies cow's milk formula unless there seems to be an allergy or intolerance, in which case the doctor may recommend soy or hypoallergenic formula. Soy formula — with added iron — is as nutritious as cow's milk-based formula. The problem is that many babies who are allergic to cow's milk are also allergic to the protein in soy formulas, so it may not be helpful in these cases.

Some parents may worry after hearing or reading about certain soy concerns, particularly about phytoestrogens (hormone-like chemicals from plants) that are found in soy formulas. These concerns need to be studied further, but so far research has not found definite evidence that soy formulas negatively affect a child's development or reproductive system.

Soy formula should be used under the direction of your doctor, but it can be an alternative to cow's milk formula for full-term infants. However, soy formulas are not recommended for premature infants.

How do I safely switch to a different formula?

Before making the decision to switch, be sure to talk to your doctor. Parents often assume that formula plays a part in a baby's fussiness, gas, spitting up, or lack of appetite. But often that's not the case.

If your doctor gives the OK to switch formulas, he or she will recommend a way to do it so that your baby's feedings and digestion aren't interrupted. The doctor may suggest mixing the two formulas together little by little, then eventually eliminating the original formula altogether.

Do I need to give my formula-fed baby vitamins?

No. Commercial infant formulas with iron are manufactured to contain all the nutrients your baby needs.

Does my baby need fluoride supplements?

Infants —whether breastfed or formula-fed — do not need fluoride supplements during the first 6 months. From 6 months to 3 years, babies require fluoride supplements only if the water supply is lacking in fluoride. Ask your doctor about what your little one needs.

Is it normal for my baby to spit up after a feeding?

Yes, many infants will spit up a little after eating or during burping because their digestive tracts are immature. This is perfectly normal. Babies may spit up when they:

have eaten too much

burp (the so-called "wet burp")

drool

cough or cry

Some babies spit up often, maybe even after every feeding. If they're happy, growing normally, and don't seem troubled by it, this usually is OK. These babies are called "happy spitters." If you find that your "spitter" seems fussy or uncomfortable after feedings, talk to your doctor to help figure out what's going on. It helps to keep a record of exactly how often and how much your baby spits up to help your doctor diagnose any problem.

Also tell the doctor if your child vomits. Vomiting is not the same as spitting up. Vomiting is a forceful projection of stomach fluids whereas spitting up is a more gentle "flow" of fluids that come up. In rare cases, vomiting is caused by a problem that needs medical attention.

If the doctor says your baby's spitting up is normal, here are some ways that may help ease it:

Burp your little one every 3 to 5 minutes during feedings.

Try giving smaller feedings more frequently.

Hold your baby upright after feedings.

Don't jiggle, bounce, or actively play with your baby right after feedings.

Make sure the nipple hole in your baby's bottle is the right size for your baby. For example, fast flows may cause babies to gag or may simply give them more than they can handle, whereas slower flows may frustrate some babies and cause them to suck harder and gulp too much air.

Keep your baby's head above his or her feet while feeding (in other words, don't hold your baby in a dipped-down position when feeding).

Raise the head of your baby's crib or bassinet. Do this by rolling up a few small hand towels or receiving blankets (or buy special wedges) to place under (noton top of) the mattress. But don't use a pillow under your baby's head, and always put your baby on his or her back to sleep.

Fortunately, many babies grow out of spitting up by the time they're 1 year old.

Is it OK to prop a bottle in my baby's mouth?

No. You shouldn't leave your baby unattended or feeding from a "propped" bottle. Propping a bottle is a choking hazard and also can lead to ear infections and baby bottle tooth decay, a serious dental condition that results from formula (as well as breast milk or juice) pooling in a baby's mouth. Always hold your baby during feedings.

It is OK to let my baby sleep with a bottle?

No. You should never put your baby to bed with a bottle. Like propping a bottle, it can cause choking, ear infections, and tooth decay.